• Journal of IKEEE
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• v.27 no.3
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• pp.234-238
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• 2023

In this paper, we propose a time-to-digital converter (TDC) with compensation capability for PVT (process, voltage, and temperature) variations. A typical delay line-based TDC measures time based on the inverter's propagation delay, making it fundamentally sensitive to PVT variations. This paper presents a method to minimize the resolution change of TDC by compensating for the propagation delay caused by the PVT variations. Additionally, it dopts Cyclic Vernier TDC (CVTDC) structure to provide a wide input detection range. The proposed CVTDC with PVT compensation function is designed using a 45nm CMOS process, consumes 8mW of power, offers a TDC resolution of 5 ps, and has an input detection range of about 5.1 ns.

• International journal of advanced smart convergence
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• v.5 no.1
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• pp.34-46
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• 2016

Networked Control System (NCS) has evolved in the past decade through the advances in communication technology. The problems involved in NCS are broadly classified into two categories namely network issues due to network and control performance due to system network. The network problems are related to bandwidth allocation, scheduling and network security, and the control problems deal with stability analysis and delay compensation. Various delays with variable length occur due to sharing a common network medium. Though most delays are very less and mostly neglected, the network induced delay is significant. It occurs when sensors, actuators, and controllers exchange data packet across the communication network. Networked induced delay arises from sensor to controller and controller to actuator. This paper presents an adaptive delay compensation process for efficient control. Though Smith predictor has been commonly used as dead time compensators, it is not adaptive to match with the stochastic behavior of network characteristics. Time delay adaptive compensation gives an effective control to solve dead time, and creates a virtual environment using the plant model and computed delay which is used to compensate the effect of delay. This approach is simulated using TrueTime simulator that is a Matlab Simulink based simulator facilitates co-simulation of controller task execution in real-time kernels, network transmissions and continuous plant dynamics for NCS. The simulation result is analyzed, and it is confirmed that this control provides good performance.

• KDI Journal of Economic Policy
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• v.33 no.3
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• pp.121-161
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• 2011

We study incentive structures of public developers and land owners in the process of public expropriations using a sequential game model. In the model, we show that there is an incentive for the public developer to give more compensation than just compensation that are defined by law. Also the model shows that there is an incentive for the land owners to revolt strategically against the public expropriation. Then an ideal authority delegation model is introduced to resolve the problems, where an independent appraiser determines the compensation for the expropriation. In the real world, improving the independence of appraisal process is critical to make the system closer to the ideal authority delegation model. So this paper concludes by making a few policy suggestions to improve the current appraisal system.

• Transactions of Materials Processing
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• v.23 no.7
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• pp.439-445
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• 2014

Changes in the accuracy of the geometrical shape after a surface treatment are often very large due to the variation of the deformation mechanisms such as edge draw-in and the variation in springback caused by the reduction in the coefficient of friction between the tool and the blank. In the present study, the resulting shape accuracy due to the changes in deformation is quantitatively examined in order to predict the variation and to remove any undesirable additional tool compensation for the center pillar member made from steel with a UTS of 980MPa. The study examines important process parameters that are closely related with the edge draw-in such as the blank holding force, the contact status between the tool and the blank and the friction coefficient. The proposed method is applied within the finite element analysis of the stamping process for tools after a surface treatment and the amount of edge draw-in and flush values are compared between the analysis and experiments. The results demonstrate that the proposed quantification and finite element scheme are applicable to complicated tool compensation procedures and compensation can be designed effectively.

• The Transactions of the Korean Institute of Power Electronics
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• v.27 no.6
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• pp.481-488
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• 2022

This study proposes compensation methods for the initial position error and torque ripple in vector control of two-phase hybrid stepping motors. Stepping motors have an asymmetrical structure due to misalignment, such as the eccentricity generated by the manufacturing and assembly process. When vector control is applied using the position information measured by an incremental encoder attached to the rotor shaft of such stepping motors, the following problems occur. First, an initial position error occurs during the forced excitation process for the initial rotor position alignment. Second, torque ripple corresponding to the mechanical rotation frequency is generated. In this study, these non-ideal phenomena that occur in vector control of the stepping motor are analyzed, and compensation methods are proposed to eliminate them. The validity of the proposed initial position error and torque ripple compensation methods is verified through experiments on a two-phase hybrid stepping motor drive system.

• The Korean Journal of Emergency Medical Services
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• v.26 no.1
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• pp.119-127
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• 2022

Purpose: This study aimed to examine the necessity of administrative compensation insurance and claims cases during the emergency medical service process among administrative compensation insurance cases and suggests problems and improvement measures. Methods: We compared the details of administrative compensation insurance claims of 15 cities and provinces, excluding Seoul and Kwangju, from 2017 to 2020 by requesting details disclosure of the comprehensive deduction for administrative compensation in 17 cities and provinces across the country. Results: A total of 69 cases were compensated through the administrative comprehensive compensation deductions. There were 53 cases of damage that occurred at the field stage, 14 cases at the transfer and hospital stage, and two other cases. Conclusion: The 119 paramedics, which are the perpetrators, should be active in field activities and free from the psychological pressure caused by increased workload and litigation. Active compensation administration is required for damage cases occurring in the firefighting activities context.

• Journal of Digital Contents Society
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• v.10 no.4
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• pp.569-578
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• 2009

In this paper, we describe the color reproduction system for color images captured by digital camera. The system uses a color compensation chart to estimate the transformation between the colors in the image and the reference colors in the chart. The color reproduction process consists of two steps, i.e., the profile creation process and the profile application process. During the pro-file creation process, the relationships between the captured colors and the ref-erence colors are estimated. And the system creates a color profile and embeds the estimation result in the profile. During the profile application process, the colors in the images which are captured under the same condition as that of the chart image are reproduced using the created color profile. To evaluate the per-formance of the system, we perform experiments under various conditions. And we compare the results with those of widely used commercial applications.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.943-946
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• 2000

Selective laser sintering(SLS) is a solid freeform fabrication process whereby a part is built layerwise by scanning a powder bed. The properties of metal powder are dependent on the heat, it is not easy to do the exact error compensation with analysis and estimation by modeling. This paper suggests that the error is compensated by experimental method and then the accuracy of shape is enhanced by revising of STL file. Also bonding force is measured by an experiment with change of process path.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.804-808
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• 1991

In a transfer line with mass production capability, calibration systems are included in the process as a separate dedicated station. However, this method is not appropriate in an unattended FMC with flexibility. As the FMC produces vesatile parts with small batch sizes, more flexible calibration systems are required. In this paper, a calibration/inspection system suitable for an unattended turning cell is introduced. The system has functions of dimension calibration of parts by touch probes, tool wear compensation, and quality monitoring of parts. Furthermore, characteristics of errors in the system are identified and corresponding compensation methodology is suggested. An operation software was developed for efficient use of the system.

• Proceedings of the IEEK Conference
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• 2000.06d
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• pp.167-170
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• 2000

In this paper, we propose the edge compensation algorithm which connects the adjacent edges without losing the information of the skeletons on the edge image. The proposed edge compensation algorithm is composed of succeeding two steps. In the first step, the uplifted image is obtained by applying the uplifting process to the edge image. The next step is to extract the edge image from the uplifted image using the skeleton extraction algorithm. Experimental results show that the proposed method connects the adjacent edges without the distortion of the original edge information compared to the traditional method